1. It's possible that they did get their power from an interurban line. The interurban would have used a higher voltage than 110VAC but all that would be needed to supply houses would be a transformer to lower the voltage. This would have been a long time ago and they were probably only using the power for lights or simple appliances (like irons or toasters) since electrical gear (anything with a motor)for homes isn't built for 25Hz.

2. The old Milwaukee electric operation had converter stations every so often, 20 or 25 miles. These were supplied commercial AC power and use motor generator sets to convert the AC to DC which was used on the catenary.

BTW, the old "DC can't be transmitted very far" isn't really true. The Bonneville Power Admin. (BPA) has a high voltage DC line that transmits power from Celilo, OR (near The Dalles) to southern California.
[www.bpa.gov]

Bill Maltby